user-centric terminology

[SitG Admin]

Another confusing thing is: what happens when users are communicating 
(aka p2p) directly with each other; "center" implies a *single* 
point, so which of them is the center? Is a center semantically 
unsuitable for that pattern of communication, or does "center" need 
to be limited in scope so it applies clearly to data which is 
uniquely belonging to one user? (Collaborative works complicate 
matters.)

-Shade